The War of the Polish Succession (1733-1738) was sparked by a Polish civil war over the succession to Augustus II, King of Poland that widened as the two Bourbon powers attempted to check the power of the Habsburgs in western Europe. The war resulted in the transfer of the Kingdom of Naples from the Habsburgs to a junior branch of the House of Bourbon.
Former Polish King Stanisław Leszczyński, hoped to be elected king once again upon the death of his old adversary, Augustus II of Saxony, who had not succeeded in making the Polish crown hereditary within his family. Thirty years before, Stanisław Leszczyński had been installed as king of Poland by King Charles XII of Sweden during his period of dominance in the early part of the Great Northern War, and ousted following Poltava by the victorious Russians. Stanisław was supported by his son-in-law, King Louis XV of France, who hoped to renew France's traditional alliance with Poland as a way to balance Russian and Austrian power in Northern and Eastern Europe.
In 1732 Empress Anna of Russia, Holy Roman Emperor Charles VI and King Frederick William I of Prussia, irritated with Augustus but unwilling to allow Stanisław to become king, decided to jointly back the candidacy of Emmanuel of Portugal for the Polish throne.
France's prime minister, Cardinal Fleury, saw the Polish struggle as a chance to strike at Austrian power in the west without seeming to be the aggressor. While he cared little for who should become King of Poland, the cause of protecting the King's father-in-law was a sympathetic one, and he hoped to use the war as a means of humbling the Austrians, and perhaps securing the long-desired Duchy of Lorraine from its duke, Francis Stephen, who was expected to marry Emperor Charles's daughter Maria Theresa, which would bring Austrian power dangerously close to the French border.
Louis XV was joined by his uncle, King Philip V of Spain, who hoped to secure territories in Italy for his sons by his second marriage to Elizabeth Farnese. Specifically, he hoped to secure Mantua for the elder son, Don Carlos, who was already Duke of Parma and had the expectation of the Grand Duchy of Tuscany, and the Kingdoms of Naples and Sicily for the younger son, Don Felipe. The two Bourbon monarchs were also joined by Charles Emmanuel III of Savoy, who hoped to secure gains from the Austrian Duchy of Milan.
Although the Austrians had hoped for aid from the maritimes powers, Great Britain and the Dutch Republic, they were disappointed, as both the Dutch and the British chose to pursue a policy of neutrality. The French, not wishing to provoke them, chose not to campaign in the Austrian Netherlands. The Austrians were thus left largely without effective allies. Their Russian and Saxon allies were still largely occupied with finishing the Polish campaign. The Emperor distrusted Frederick William I of Prussia, who was willing to provide aid but provided only nominal support. The Bavarians and other medium-sized German states were committed to neutrality by an alliance with France, leaving only a few small German states - and the Electorate of Hanover, where George II proved willing to help in his role as an Imperial Elector - to support the Emperor.
Augustus II died on February 1, 1733, and the Polish nobles, led by primate Teodor Potocki, gathered for the election. The Russians and Austrians, seeing the strong support for Leszczyński, gave up their support of Emmanuel of Portugal and turned to Frederick Augustus of Saxony, the previous king's son and the only plausible alternative candidate. The Russian and Austrian armies were mobilized to intimidate the diet, but it chose Leszczyński anyway.
The Russian army under Field Marshal Peter Lascy entered Polish territory in order to support the claims of Frederick Augustus of Saxony. A group of nobles, mainly Lithuanian magnates led by Duke Michael Wiśniowiecki (the former Lithuanian grand chancellor nominated by Augustus II), left the place of election to join the Russians. This group elected Frederick Augustus King of Poland as Augustus III. Despite the fact that this group was a minority, the Russians and Austrians, intent on maintaining their influence within Poland, recognised Augustus as king.
The Russians, led by Munnich, quickly took Warsaw and installed Augustus, forcing Stanisław to flee to Danzig,-Prussia, now Gdańsk Poland, where he was besieged for some time by a Russian-Saxon army. Danzig was occupied in June 1734, and Stanisław fled to his son-in-law in France.
The war in Poland was largely over, and was an unambiguous victory for the Russians and their candidate. A group of nobles supporting Stanisław formed the Confederation of Dzikow (1734) and under their commander, Adam Tarło, tried to fight the Russians and Saxons, but their efforts were ineffective.
In spite of the quick Russian victory, the war did not end, however. The war proved a disaster for the Austrians. Due to the neutrality of the Netherlands, it was fought largely on two fronts - on the Rhine and in Italy. The Rhine campaigns saw the last appearance in the field of two great generals of the previous generation, Prince Eugene of Savoy and the Duke of Berwick — the latter was killed at the siege of Philippsburg — and the baptism of fire of the young crown prince of Prussia, the later Frederick the Great. The French were largely successful - they overran Lorraine and captured the important fortress of Philippsburg on the right bank of the Rhine.
In Italy, the Austrian situation was even worse. In the north, there were two hard-fought though indecisive battles: the Austrians won the Battle of Parma (or San Pietro) (June 29, 1734) and the French and their allies won the Battle of Luzzara (or Guastalla) (September 19, 1734). But in the south, the Austrians lost disastrously, with the Spanish easily defeating them at Bitonto and conquering Naples and Sicily by May 1734.
With the Austrians being in no real position to continue the fight, and the French concerned by the possible arrival of Russian reinforcements, which did indeed arrive on the Rhine for the first time in this campaign, peace negotiations soon began.
A preliminary peace was concluded in October 1735 and ratified in the Treaty of Vienna (November 1738). Augustus was confirmed as king of Poland, Stanisław being compensated with the Duchy of Lorraine (which would thus pass, on his death, through his daughter to the French), while the former Duke of Lorraine, Francis Stephen, was made heir to the Grand Duchy of Tuscany, which he inherited in 1737.
Charles III of Spain was forced to give up not only his rights to Tuscany but also his previous Duchy of Parma, which came under direct Austrian rule, but he was richly compensated by being confirmed instead as king of Naples and Sicily. Philip of Parma was abandoned, receiving nothing. Although fighting stopped after the preliminary peace in 1735, the final peace settlement had to wait until the death of the last Medici Grand Duke of Tuscany, Gian Gastone in 1737, to allow the territorial exchanges provided for by the peace settlement to go into effect.
The French (and their allies), hoping for détente and good relations with the Austrians, now recognized the Pragmatic Sanction that would allow Emperor Charles's daughter Maria Theresa to succeed him. This proved a hollow guarantee, however, as the French decided to intervene to partition the Habsburg Monarchy after all following Charles's death in 1740. The acquisition of Lorraine for the former Polish king, however, proved of lasting benefit to France, as it passed under direct French rule with Stanisław's death in 1766.
In Poland in 1736 Stanisław signed the act of abdication, while Augustus III pronounced a general amnesty. Wiśniowiecki was rewarded: the king made him the Grand Hetman (commander-in-chief) of Lithuania.